The Sun
Tops Global Warming Causes

This page presents a more scientific point of view, on the role of our Sun among global warming causes, than my own humble opinion on the natural causes of global warming, on another page of this web site.

To begin with, may I recommend
the complete introductory course on Earth's Changing Climate!

Summer sunset picture by Claude Jollet.

We are learning more each day about how our universe works. The more we discover, the more we realize that we know very little!

Researchers are finding that there is more to our changing climate … than meets the eye, at first glance. Our sun's behavior is among the top "suspect". And, even it, is under influences originating outside our solar system!

Solar energy varies over time … long periods of time, hundreds of thousands of years!

Earth's atmosphere, and thus its climate, are affected by this varying amount of energy.

Furthermore, the characteristics of the Earth's orbit around the Sun also varies over time. This phenomenon has an additional effect on our climate, because it is another cause behind the varying amount of solar energy our planet receives. This phenomenon is known as "Milankovitch forcing", in scientific circles. It comes in as a close second, behind our Sun, among global warming causes.

Milankovitch first published his theory in 1920. Later investigations of deep-sea sediments, made in the 1970s, brought "to the surface" supporting proof of his theory. It has been widely accepted, since then.

Finally, as if to further complicate matters, these two varying factors, mentioned above, periodically come into relative phase. By this, I mean that they will occasionally, over tens of thousands of years, or more, occasionally combine their effects to cause even higher peaks of warming, and cooling, in our climate.

Considerable research has been already been done on the causes of our climate changes. Even more is currently undergoing.

Allow me submit the following abstract to you. Please consider it as one of many conclusions of scientific research being done on global warming causes.

"Direct observations of sunspot numbers are available for the past four centuries, but longer time series are required, for example, for the identification of a possible solar influence on climate and for testing models of the solar dynamo. Here we report a reconstruction of the sunspot number covering the past 11,400 years, based on dendro-chronologically dated radiocarbon concentrations.

We combine physics-based models for each of the processes connecting the radiocarbon concentration with sunspot number. According to our reconstruction, the level of solar activity during the past 70 years is exceptional, and the previous period of equally high activity occurred more than 8,000 yearsago. We find that during the past 11,400 years the Sun spent onlyof the order of 10% of the time at a similarly high level ofmagnetic activity and almost all of the earlier high-activityperiods were shorter than the present episode.

Although the rarity of the current episode of high average sunspot numbers may indicate that the Sun has contributed to the unusual climate change during the twentieth century, we point out that solar variability is unlikely to have been the dominant cause of the strong warming during the past three decades".

(Words in bold are mine).

Solanki, S.K., et al. 2005.11,000 Year Sunspot Number Reconstruction.IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series #2005-015. Source: NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.

The abstract above is one of many that are available at the The NOAA Paleoclimatology Program archives data on climate forcing. (, where you can obtain access to a variety of data about factors potentially affecting climate, and of being potential global warming causes, such as:

  • volcanic eruptions,
  • solar variability,
  • trace gasses and aerosols,
  • and Milankovitch orbital variations.


Photo by Nancy Weiner. INSTAAR, University of Colorado, Boulder Source: National Oceanic and Atmospheric Administration Paleoclimatology.
Photo by Nancy Weiner

Paleoclimatology is the study of past climate, for times prior to instrumental weather measurements.

Paleoclimatologists use clues from natural "proxy" sources such as tree rings, ice cores, corals, and ocean and lake sediments to understand natural climate variability, and global warming causes.

The paleoclimate records show that rapid and dramatic changes in climate conditions have occurred Earth, as far as science can see back in the past, that is, over the past 400,000 to 600,000 years.

The graph below shows analysis of of ice core data from Vostok, Antarctica, a Russian research station located near the South Geomagnetic Pole, at the center of the East Antarctic Ice Sheet.

Graph of analysis of ice cores from Vostok Russian scientific station in Antartica. Source: Wikipedia.ord

At present, we are on the left hand edge of the graph … looking back at evidence of dramatic climatic changes. We are left with the task of finding what were the global warming causes, and its effects on our climate.

Notice the peaks of temperature (in red), and of atmospheric carbon dioxide (CO2 in blue), that have been found to occur around 130,000, 240,000, and 325,000 years ago?

This may come as a shock to those who blame man as entirely responsible for our global warming. Man couldn't possibly have been responsible for those recurring increases in temperature and CO2 of such distant past!

What Is The Main Cause Of Global Climatic Changes?

This page will have, hopefully, provided you with some solid, scientifically supported leads. If you feel confused, remember this. Scientists from around the world are actively looking into the global warming causes … because they are still not satisfied with the answers they have come up with to this day! But the Sun remains a top suspect!

Stay tuned, and keep a sharp weather watch!

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